Choose a mailbox tier and a billing term, and the figure below is the figure on the invoice. Adding a teammate never changes it.
- No card to start
- Cancel from settings
- Overage billed monthly
Three plans, two dials
Set your mailbox tier and billing term once, and every price on this page recalculates from the same table, live.
Quarterly saves 10%, yearly is two months free. Mailboxes past the included count bill monthly at the per-mailbox rate, whichever term you pick.
Starter
One domain, one offer, and ten sending identities to prove it works.
Billed monthly
Start with Starter10 standard mailboxes included
then $3.50 per extra mailbox/mo
What’s included
Growth
Several offers in flight, spread across domains so none of them share a fate.
Billed monthly
Start with Growth30 standard mailboxes included
then $3.25 per extra mailbox/mo
What’s included
Scale
Dozens of domains, ramp curves you define, and an audit trail behind every change.
Billed monthly
Start with Scale100 standard mailboxes included
then $3.00 per extra mailbox/mo
What’s included
Enterprise
Custom mailbox volume, IPs reserved to your contract, a named onboarding engineer and paperwork that survives your procurement process.
The basics are not the upsell
Starter, Growth and Scale ship the same provisioning, authentication and monitoring. Higher tiers buy capacity, ramp posture and support depth, never a feature back.
Workspace isolation
One workspace per client or campaign, each holding its own domains, billing and access list. Nothing crosses the boundary.
DNS and auth automation
SPF, DKIM, DMARC, MTA-STS and BIMI are generated per domain, published for you, then re-checked on a schedule so drift surfaces before a campaign does.
Bulk mailbox provisioning
Name a pattern, set a count. Accounts, aliases, signatures and photos are created in a single job, at any plan's volume.
Warmup on every mailbox
Every mailbox ramps on a private peer network before it carries real volume. Standard on Starter, accelerated or custom above it.
Continuous health checks
Blocklists, MX records and DNS drift are watched around the clock on every plan. There is no monitoring add-on to unlock.
Role-based access and audit log
Owners, operators and viewers scoped per workspace, with every provisioning action and setting change attributed and timestamped.
Also on every plan
- Instant provisioning
- Domain forwarding
- Unified inbox export
- API access
- Bulk profile editing
- Standard email support
Where each tier's limits actually sit
The row you came for is probably the one about caps, seats or how fast support answers.
Drag the table sideways to reach every tier
| Capability | Starter | GrowthPopular | Scale | Enterprise |
|---|---|---|---|---|
| Provisioning | ||||
| Included mailboxes | 10 | 30 | 100 | Custom |
| Sending domains | 1 | Up to 5 | Unlimited | Unlimited |
| Time to first send | < 10 min | < 10 min | < 5 min | < 5 min |
| Bulk mailbox editing | ||||
| Custom sender naming | ||||
| Deliverability | ||||
| Ramp curve | Standard | Accelerated | Custom curves | Custom curves |
| Warmup peer network | Shared | Shared | Shared or dedicated | Dedicated |
| Domain health alerts | ||||
| Reputation analytics | Basic | Standard | Advanced | Advanced |
| Dedicated IP pool | Add-on | |||
| Automation | ||||
| Auth records published for you | ||||
| Domain forwarding with tagging | ||||
| REST API access | ||||
| Signed webhooks | ||||
| Security & support | ||||
| Role-based access | 2 roles | Up to 10 seats | Unlimited seats | Unlimited seats |
| Audit log | ||||
| Single sign-on | ||||
| Support response | 1 business day | 4 hours | 1 hour | Dedicated channel |
Provisioning
Included mailboxes
- Starter
- 10
- Growth
- 30
- Scale
- 100
- Enterprise
- Custom
Sending domains
- Starter
- 1
- Growth
- Up to 5
- Scale
- Unlimited
- Enterprise
- Unlimited
Time to first send
- Starter
- < 10 min
- Growth
- < 10 min
- Scale
- < 5 min
- Enterprise
- < 5 min
Bulk mailbox editing
- Starter
- Growth
- Scale
- Enterprise
Custom sender naming
- Starter
- Growth
- Scale
- Enterprise
Deliverability
Ramp curve
- Starter
- Standard
- Growth
- Accelerated
- Scale
- Custom curves
- Enterprise
- Custom curves
Warmup peer network
- Starter
- Shared
- Growth
- Shared
- Scale
- Shared or dedicated
- Enterprise
- Dedicated
Domain health alerts
- Starter
- Growth
- Scale
- Enterprise
Reputation analytics
- Starter
- Basic
- Growth
- Standard
- Scale
- Advanced
- Enterprise
- Advanced
Dedicated IP pool
- Starter
- Growth
- Add-on
- Scale
- Enterprise
Automation
Auth records published for you
- Starter
- Growth
- Scale
- Enterprise
Domain forwarding with tagging
- Starter
- Growth
- Scale
- Enterprise
REST API access
- Starter
- Growth
- Scale
- Enterprise
Signed webhooks
- Starter
- Growth
- Scale
- Enterprise
Security & support
Role-based access
- Starter
- 2 roles
- Growth
- Up to 10 seats
- Scale
- Unlimited seats
- Enterprise
- Unlimited seats
Audit log
- Starter
- Growth
- Scale
- Enterprise
Single sign-on
- Starter
- Growth
- Scale
- Enterprise
Support response
- Starter
- 1 business day
- Growth
- 4 hours
- Scale
- 1 hour
- Enterprise
- Dedicated channel
Add the piece, not the whole tier
When one client or one campaign needs more than the plan holds, buy the capacity by itself and leave the tier where it is.
Extra mailboxes
Sending identities past the included count, billed per mailbox each month with no tier change.
6 of 10 new slots filled
Dedicated IP pool
A pool no other customer sends from, so reputation tracks your own volume alone.
Deliverability test credits
Seed-list runs against the major providers, on demand, for when you need proof not a hunch.
AI insight credits
A written root-cause note the moment a domain's health score moves the wrong way.
“Domain risk rising: DKIM alignment drifted 2 days ago.”
The answers that decide the plan
Overage, cancellation, terms and invoices: the details worth knowing before you pick.
Nothing is blocked and no send stops. Mailboxes past the included count are created at the plan's per-mailbox rate and appear as a usage line on your next invoice. Move up a tier when that line grows past the gap between plans.
Per mailbox, per month, at the rate printed on the plan card. Overage bills monthly even on a quarterly or yearly term, so a longer commitment never locks you into capacity you haven't provisioned yet.
Yes. Every domain is registered under your account, not ours. Ask for the authorization code and the transfer to another registrar takes minutes. Leaving Infrabox never puts your sending names at risk.
A yearly term is two months free and a quarterly one saves 10%, both on the base plan only. If your mailbox count is still moving week to week, stay monthly. Overage is priced the same on every term.
Mailboxes keep sending until the term you've already paid for ends, then the fleet is paused rather than deleted. If a plan turned out wrong, ask within 14 days of the first charge and we reverse it in full.
Upgrades charge only the prorated difference for the days left in the period and unlock as soon as payment clears. Downgrades credit the unused difference and switch over at the end of the paid term.
Yearly plans can be invoiced on net-30 terms for teams that need a purchase order on file. Ask your account contact to change the billing method before the next renewal.
It's pre-tax. Sales tax or VAT is worked out from your billing address and shown as its own line before you confirm any charge. Nothing else is added on top.
Start on the tier this month needs
No card to provision your first domain. Change tier, add mailboxes or scale back the moment your sending volume moves.
- No card to provision
- Change tier any time
- Cancel from settings